A low pressure are in the West Philippine Sea developed into a Tropical Depression "Mun" last July 1, 2019. It moved westnortwest while gaining strength. It made landfall and crossed Hainan Island the next day . On July 3, 2019, it gained enough streght and was upgraded to Tropical storm while traversing the Gulf of Tokin. On July 4, 2019, it made its second landfall in northern Vietnam then weakened before it dissipated late on that day.